The shipping industry uses large cargo containers to ship cargo from one location to another in domestic and global commerce. Such containers are designed to be conveniently moved from one mode of transport to another across the land by road or on rail or over the sea. Such containers are sometimes referred to as “intermodal shipping containers”. The use of such containers has essentially eliminated the need for manually transferring cargo from one vessel to another, or from one vehicle or railcar to another in the effort to deliver the cargo to its final destination.
Today, cargo containers are generally standardized by internationally recognized standards, and by national domestic standards with respect to dimensions and structure. Thus, the standard containers can be securely arranged in vertical stacks in side-by-side and end-to-end relationship with each other, and can be handled most effectively when transferring from one mode of transport to another.
Often, these containers must be transported empty from one delivery point to the next location where cargo is available for shipment. Transport of empty containers costs the shipper money and erodes profits since transport of each such container incurs handling cost and occupies valuable space which could otherwise be used to ship a revenue producing container loaded with cargo. Additionally, the shipping of both loaded and empty containers creates problems such as how to arrange the lighter, empty containers and the heavier, loaded containers aboard ships in such a manner that the safety of the ships is not compromised. Beyond safety issues, the shipment of empty containers causes monetary losses for shippers, losses which result in either substantial financial impact on the shipper, or increased charges to customers for the handling and transport of loaded containers. Similar cost disadvantages apply when shipping empty containers over road or by rail.
Long ago shippers recognized that significant economic savings in shipping could be realized if empty containers could be “folded” so as to occupy a substantially smaller space, so that less space need be sacrificed in the transporting of empty containers. Such an effort presently exists only for the “open frame” or flat rack type containers. To that end, the prior art proposed many foldable or nesting cargo containers of the enclosed types intended to reduce the space required for their shipment when empty. While such prior art foldable containers have been proposed, the market has not embraced the prior art containers as a substitute for the standard, non-foldable cargo containers.
One common shortcoming in most foldable container designs is that structural features are incorporated in them which render the designs nearly incompatible for use in combination with existing, standard cargo containers. Accordingly, if these cargo containers were to become a part of the norm, they could not be used with existing standard containers, making the cost of implementation of these designs impractical, if not prohibitive.
Another shortcoming of foldable containers of the prior art is the lack of structural designs which enable or facilitate the folding and un-folding of such containers in a simple and effective manner with commonly available equipment.